Based on analysis of a live migration (v1.2.42 -> v1.2.47):
1. Absolute worktree paths: Bash tool resets cwd between calls,
so relative cd .upgrade-worktree fails. Store PROJECT_ROOT and
WORKTREE as absolute paths, use them throughout.
2. Smarter tier assessment: discount files from skill merges when
counting — a fork with 3 skills and no other changes is Tier 2,
not Tier 3 just because 24 files changed.
3. Inter-skill conflict analysis: new "Skill Interactions" section
in the migration guide captures conflicts between applied skills
(duplicate declarations, conflicting env var handling).
4. Cleaner swap recipe: use git reset --hard to the upgrade commit
instead of git checkout -B intermediate branch. Backup tag
preserves rollback. Copy guide to /tmp before worktree removal.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Replaces merge-based upgrades with a two-phase approach:
1. Extract: analyzes user's fork, captures customizations as a
migration guide (intent + implementation details in markdown)
2. Upgrade: checks out clean upstream in a worktree, reapplies
customizations from the guide, validates, and swaps in
Key features:
- Tiered complexity (lightweight/standard/complex)
- Sub-agent exploration with haiku for efficient analysis
- Incremental guide updates instead of full re-extraction
- Live e2e testing via worktree symlinks before swapping
- New-changes guard prevents losing unrecorded work
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
